Related Experiment Video
Updated: May 21, 2026

Transient Expression in Nicotiana Benthamiana Leaves for Triterpene Production at a Preparative Scale
Published on: August 16, 2018
Functional characterization of amyrin synthase involved in ursolic acid biosynthesis in Catharanthus roseus leaf
Fang Yu1, Antje M K Thamm, Darwin Reed
1Department of Biological Sciences, Brock University, St. Catharines, ON, Canada. fyu@brocku.ca
Abstract:
Catharanthus roseus accumulates high levels of the pentacyclic triterpene, ursolic acid, as a component of its wax exudate on the leaf surface. Bioinformatic analyses of transcripts derived from the leaf epidermis provide evidence for the specialized role of this tissue in the biosynthesis of ursolic acid. Cloning and functional expression in yeast of a triterpene synthase derived from this tissue showed it to be predominantly an α-amyrin synthase (CrAS), since the α-amyrin to β-amyrin reaction products accumulated in a 5:1 ratio. Expression analysis of CrAS showed that triterpene biosynthesis occurs predominantly in the youngest leaf tissues and in the earliest stages of seedling development. Further studies using laser capture microdissection to harvest RNA from epidermis, mesophyll, idioblasts, laticifers and vasculature of leaves showed the leaf epidermis to be the preferred sites of CrAS expression and provide conclusive evidence for the involvement of this tissue in the biosynthesis of ursolic acid in C. roseus.
More Related Videos
07:59A Customizable Approach for the Enzymatic Production and Purification of Diterpenoid Natural Products
Published on: October 4, 2019
09:27Functional Complementation Analysis (FCA): A Laboratory Exercise Designed and Implemented to Supplement the Teaching of Biochemical Pathways
Published on: June 24, 2016
Related Concept Videos
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Amino Acid Biosynthetic Pathways
Biosynthesis of Nucleic Acids
The Citric Acid Cycle: Output
Regulation of Citric Acid Cycle
The citric acid cycle is regulated in several ways, including feedback inhibition, regulation of enzyme activities, and associated anaplerotic or cataplerotic pathways.
The primary substrate of the TCA cycle—acetyl CoA—is produced by the...
Urea Cycle
The Citric Acid Cycle: Overview
The citric...